Key Concepts in Physics

Branches of Physics
- Classical Mechanics: Study of motion, forces, energy, and momentum.
- Electromagnetism: Interaction of electric charges and magnetic fields.
- Thermodynamics: Study of heat transfer, energy conservation, and systems.
- Quantum Mechanics: Behavior of particles on atomic and subatomic levels.
- Relativity: Study of the effects of gravity and high speeds on time and space.
Fundamental Principles
- Newton's Laws of Motion:
  - First Law: An object at rest stays at rest; an object in motion stays in motion unless acted upon.
  - Second Law: Force equals mass times acceleration (F=ma).
  - Third Law: For every action, there is an equal and opposite reaction.
- Conservation Laws:
  - Conservation of Energy: Energy cannot be created or destroyed, only transformed.
  - Conservation of Momentum: Total momentum in a closed system remains constant.
Key Equations
- Kinematic Equations (for uniformly accelerated motion):
  1. ( v = u + at )
  2. ( s = ut + \frac{1}{2}at^2 )
  3. ( v^2 = u^2 + 2as )
- Ohm's Law: ( V = IR ) (Voltage = Current x Resistance)
- Ideal Gas Law: ( PV = nRT ) (Pressure x Volume = moles x gas constant x Temperature)
Units of Measurement
- SI Units:
  - Length: meter (m)
  - Mass: kilogram (kg)
  - Time: second (s)
  - Electric Current: ampere (A)
  - Temperature: kelvin (K)
  - Amount of Substance: mole (mol)
- Commonly used derived units:
  - Velocity: meters per second (m/s)
  - Force: newton (N)
  - Energy: joule (J)
Important Concepts
- Work: Work is done when a force is applied over a distance (( W = Fd )).
- Power: Rate at which work is done (( P = \frac{W}{t} )).
- Waves: Disturbances that transfer energy through space (characterized by wavelength, frequency, and amplitude).
- Light: A form of electromagnetic radiation, exhibiting wave-particle duality.
Applications of Physics
- Engineering: Application of principles to design and build structures, machines, and systems.
- Medicine: Use of diagnostic tools (like MRI, X-rays) based on physical principles.
- Technology: Development of electronic devices using concepts of electromagnetism and quantum mechanics.

Branches of Physics

Classical Mechanics: Investigates motion, forces, energy, and momentum.
Electromagnetism: Examines the interactions between electric charges and magnetic fields.
Thermodynamics: Focuses on heat transfer, energy conservation, and the behavior of systems involving heat.
Quantum Mechanics: Studies the behavior and properties of particles at atomic and subatomic scales.
Relativity: Analyzes how gravity and high speeds affect time and space.

Fundamental Principles

Newton's Laws of Motion:
- First Law: Objects at rest or in uniform motion remain so unless acted upon by a force.
- Second Law: Force (F) is equal to mass (m) multiplied by acceleration (a): ( F = ma ).
- Third Law: Every action has an equal and opposite reaction.
Conservation Laws:
- Conservation of Energy: Energy cannot be created or destroyed, only transformed from one form to another.
- Conservation of Momentum: The total momentum of a closed system is constant over time.

Key Equations

Kinematic Equations: For uniformly accelerated motion:
- ( v = u + at ) (Final velocity ( v ) equals initial velocity ( u ) plus acceleration ( a ) times time ( t )).
- ( s = ut + \frac{1}{2}at^2 ) (Displacement ( s ) is influenced by initial velocity ( u ) and acceleration ( a )).
- ( v^2 = u^2 + 2as ) (Relationship between initial velocity, acceleration, and displacement).
Ohm's Law: Defines electrical relationships as ( V = IR ) (Voltage ( V ) equals current ( I ) times resistance ( R )).
Ideal Gas Law: Describes the behavior of ideal gases: ( PV = nRT ) (Pressure ( P ) times volume ( V ) equals moles ( n ) times the gas constant ( R ) times temperature ( T )).

Units of Measurement

SI Units:
- Length: meter (m)
- Mass: kilogram (kg)
- Time: second (s)
- Electric Current: ampere (A)
- Temperature: kelvin (K)
- Amount of Substance: mole (mol)
Derived Units:
- Velocity: meters per second (m/s)
- Force: newton (N)
- Energy: joule (J)

Important Concepts

Work: The product of force and displacement (( W = Fd )), representing energy transfer.
Power: The rate at which work is done, expressed as ( P = \frac{W}{t} ).
Waves: Energy disturbances characterized by wavelength, frequency, and amplitude.
Light: A type of electromagnetic radiation that exhibits both wave-like and particle-like properties.

Applications of Physics

Engineering: Utilizes physical principles to create structures, machines, and various systems.
Medicine: Employs diagnostic technologies (e.g., MRI, X-rays) grounded in physics principles.
Technology: Advances electronic devices through the concepts of electromagnetism and quantum mechanics.